That the result would be death, and a death of more than customary bitterness, I knew too well the character of my judges to doubt. The mode and the hour were all that occupied or distracted me.

The narrator has this thought not long after he awakens in the chamber for the first time. At this moment, he’s imprisoned in complete darkness, with little ability to understand the space he’s trapped in or calculate the passage of time. Nevertheless, he knows he’s been sentenced to death. Even before the more frightening torments of the story begin, the monks have already begun their manipulation, leaving the narrator alone to wonder how and when they will strike.

I knew that surprise, or entrapment into torment, formed an important portion of all the grotesquerie of these dungeon deaths.

The narrator has this thought not long after noticing the pendulum for the first time and understanding its significance as an instrument of death. Here, he observes that part of what makes the torture of the Inquisition so terrible is the psychological element. The inquisitors do not merely kill their prisoners but force them into surprising and horrifying situations that are terrifying to comprehend in addition to being painful. The monks manipulate their victims with fear, anticipation, and surprise.

But it might have been long; for I knew there were demons who took note of my swoon, and who could have arrested the vibration at pleasure.

The narrator has this thought after he wakes to find himself bound beneath the pendulum. He notes that he cannot fairly judge how long he had been unconscious because it’s likely the monks stopped the pendulum temporarily, wanting him to be awake for every moment of its descent. The purpose of only allowing the pendulum to drop while the narrator is conscious is to force him to watch and wait as it descends. The slowness gives the narrator ample time to contemplate and surrender to his fate, imagining the pain that awaits him.